Animation not responding in time?
The reason for this is that there is a big difference between frames and logic ticks. There is a default of 60 logic ticks per second, and 20 frames per second.

The current frame rate in your scene can be found here in case you accidentally changed it, but the default is 20.



If you add a delay sensor, and hover over the
 delay field, the tool tip that opens shows this:



The relation here is three logic ticks for every one frame. So for your mouse sensor, it should have the true level triggering set to 15 for 5 frames to play on your action actuator

You can avoid this by changing your mouse sensor's delay between positive pulses from 5 to 15